Drum washing machine

ABSTRACT

A drum washing machine in which washing water is supplied directly to a drum to reduce consumption of the washing water, and is easily discharged from the drum in a dehydrating mode without leakage of the washing water from the drum in a washing mode. The drum washing machine includes an opening and closing device to open the dehydration holes by a centrifugal force only when the drum is rotated more than a designated speed. The opening and closing device includes opening and closing members to open and close the dehydration holes, and an elastic member to enable the opening and closing members to open and close the dehydration holes according to an intensity of the centrifugal force generated due to a rotation of the drum. The drum washing machine supplies the washing water directly to the drum, thereby preventing problems regarding the leakage or discharge of the washing water.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of Korean Patent Application No.10-2005-0072297, filed Aug. 8, 2005, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a drum washing machine. More particularly, to a drum washing machine in which washing water is supplied directly to a drum therein so as to reduce consumption of the washing water, and is easily discharged from the drum in a dehydrating mode without the leakage of the washing water from the drum in a washing mode.

2. Description of the Related Art

Washing machines are apparatuses for washing laundry using electricity, and are generally divided into vertical shaft washing machines, in which a rotary tub is vertically installed in a main body, and drum washing machines, in which a rotary tub is horizontally installed in a main body. In a conventional drum washing machine, a rotary tub, which is horizontally installed in a main body, is rotated in the clockwise and counterclockwise directions alternately so that laundry together with washing water vertically moves along the inner cylindrical surface of the rotary tub, thereby washing the laundry.

FIG. 1 illustrates a schematic sectional view of a conventional drum washing machine. As shown in FIG.1, the conventional drum washing machine includes a tub 2 installed in a housing 1 for storing washing water, a drum 3 rotatably installed in the tub 2 such that the drum 3 is spaced from the tub 2 by a designated interval, and a washing water supply device 4 for supplying the washing water to the tub 2. A plurality of holes 3 a is formed through the drum 3 so that the washing water flows into or out of the drum 3 in a washing or dehydrating mode.

When the drum washing machine is operated so that the washing water is supplied from the washing water supply device 4 to the tub 2, the washing water flows into the drum 3 through the holes 3 a and the drum 3 is rotated by a motor 5, thereby washing laundry in the drum 3. When the washing water is discharged from the drum 3 after the washing operation, the washing water in the drum 3 is discharged to the tub 2 through the holes 3 a, and the washing water in the tub 2 is then discharged to the outside through a drainage tube 6 connected to the tub 2.

Since the washing water, which is stored in the tub 2 installed outside the drum 3, flows into the drum 3 and is supplied to the drum 3, the above conventional drum washing machine is disadvantageous in that washing water of an amount larger than the substantially necessary amount for washing laundry is consumed.

In order to solve the above problem, a drum washing machine, in which washing water is directly supplied to a drum so as to reduce washing water consumption, has been developed. In this case, it is important how the washing water is discharged from the drum to the outside.

The above drum washing machine is disclosed in Korean Patent Laid-open Publication No. 2004-107650. Such a conventional drum washing machine includes a drum obliquely installed in a tub for performing washing and dehydrating operations using washing water supplied to an oblique level. A drainage hole for discharging the washing water by centrifugal force in the dehydrating operation is formed through the upper portion of the drum.

Since the drainage hole is opened even in the washing operation, the above drum washing-machine is disadvantageous in that the washing water in the drum is undulated by the movement of laundry and discharged to the outside of the drum through the drainage hole in the washing operation. Then, the appropriate amount of the washing water in the drum cannot be maintained, and the washed state of the laundry is poor.

Further, since the drainage hole is formed through the upper portion of the drum of the above conventional drum washing machine and most of the washing water is located in the lower portion of the drum, the discharging efficiency of the washing water in the dehydrating operation is reduced.

SUMMARY OF THE INVENTION

Accordingly, it is an aspect of the present invention to provide a drum washing machine in which washing water is directly supplied to a drum so as to reduce unnecessary consumption of the washing water.

Additional aspects and/or advantages of the invention will be set forth in part in the description which follows and, in part, will be apparent from the description, or may be learned by practice of the invention.

The foregoing and/or other aspects of the present invention are achieved by providing a drum washing machine, in which washing water in a drum is not discharged to an outside in a washing operation and is discharged to the outside in a dehydrating operation.

It is an aspect of the present invention to provide a drum washing machine including a housing and a drum rotatably installed in the housing, wherein a plurality of dehydration holes for discharging washing water is formed through the drum, and the drum washing machine includes an opening and closing device to open the dehydration holes by applying a centrifugal force only when the drum is rotated more than a designated speed.

The opening and closing device opens the dehydration holes only when the drum is rotated more than the designated speed, i.e., in a dehydrating mode, and the dehydration holes are closed when the drum is rotated at a low speed, i.e., in a washing mode, thereby preventing the washing water from being discharged to the outside of the drum.

The opening and closing device includes opening and closing members to open and close the dehydration holes, and an elastic member to enable the opening and closing members to open and close the dehydration holes according to an intensity of the centrifugal force generated due to a rotation of the drum.

The dehydration holes are formed through a front portion of the drum.

The elastic member includes an elastic band wound on an outer cylindrical surface of the drum at a position corresponding to the dehydration holes to apply an elastic force towards a center of the drum.

The opening and closing members are disposed between the dehydration holes and the elastic band. The opening and closing members include spherical shapes, and when the opening and closing members are mounted on the dehydration holes, the opening and closing members are partially inserted into the drum through the dehydration holes so that the washing water in the drum is not discharged to the outside of the drum.

The opening and closing members are attached to the elastic band at positions corresponding to the dehydration holes. The dehydration holes are aligned in a line along a circumferential surface of the drum.

The elastic band is fixed to the drum by connection means. The drum washing machine further includes lifters fixed to an inside of the drum for lifting laundry in the drum to a designated height, wherein the elastic band and the lifters are fixed to the drum by a same connection means.

The opening and closing device further includes sealing members interposed between the dehydration holes and the opening and closing members.

BRIEF DESCRIPTION OF THE DRAWINGS

These and/or other aspects and advantages of the invention will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings in which:

FIG. 1 illustrates a schematic sectional view of a conventional drum washing machine;

FIG. 2 illustrates a perspective view of a drum washing machine in accordance with an embodiment of the present invention;

FIG. 3 illustrates a sectional view of the drum washing machine shown in FIG. 2;

FIG. 4 illustrates an exploded perspective view of outer and inner surfaces of a drum of the drum washing machine shown in FIG. 2;

FIG. 5 illustrates a cross sectional view taken along the line I-I of FIG. 4;

FIG. 6A illustrates a view of an opening and closing member which closes a dehydration hole of the drum washing machine shown in FIG. 2; and

FIG. 6B illustrates a view of the opening and closing member which opens the dehydration hole of the drum washing machine shown in FIG. 2.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Reference will now be made in detail to the embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout. The embodiments are described below to explain the present invention by referring to the figures.

Reference will now be made in detail to the embodiment of the present invention, an example of which is illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout. The embodiment is described below to explain the present invention by referring to the figures.

FIG. 2 illustrates a perspective view of a drum washing machine in accordance with an embodiment of the present invention, and FIG. 3 illustrates a sectional view of the drum washing machine shown in FIG. 2.

As shown in FIGS. 2 and 3, the drum washing machine of the present invention comprises a housing 10 forming the external appearance of the washing machine, a tub 11 installed in the housing 10, and a drum 20 rotatably installed in the tub 11 to wash laundry therein.

The drum 20 stores washing water supplied thereto, and is rotated in the clockwise or counterclockwise direction to wash the laundry. A plurality of dehydration holes 21 is formed through a circumferential surface of the drum 20. The dehydration holes 21 discharge the washing water, and are opened by an opening and closing device 40 (see FIG. 4) only in a dehydrating mode. The opening and closing device 40 will be described later in detail.

The dehydration holes 21 are formed through a front portion of the drum 20, in consideration of the fact that the washing water moves toward the front portion of the drum 20 by centrifugal force when the drum 20 is rotated.

A door 12 to open and close an opened front surface of the housing 10 is installed on the front surface of the housing 10, and a controller 13 to control an operation of the washing machine is installed on an upper portion of the front surface of the housing 10.

A water supply tube 14 and a detergent supply device 15 to supply the washing water and a detergent to the drum 20 are installed in an upper portion of the inside of the housing 10, and a drainage pump 16 and a drainage tube 17 to discharge the washing water, which is discharged from the drum 20 to the outside of the housing 10, are installed in a lower portion of the inside of the housing 10.

A driving motor 18 to rotate the drum 20 in a clockwise or counterclockwise direction is provided outside the tub 11, and a rotary shaft 18 a to transmit a rotary force of the driving motor 18 to the drum 20 is installed between the drum 20 and the driving motor 18. A bearing 19 for rotatably supporting the rotary shaft 18 a is installed on a circumference of the rotary shaft 18 a.

A plurality of lifters 30 is installed on an inner cylindrical surface of the drum 20. The lifters 30 serve to lift the laundry and the washing water towards the upper portion of the drum 20 and drop the laundry and the washing water from a designated height by the rotation of the drum 20, thereby allowing the laundry to be washed.

When the washing machine is operated after the laundry is put into the drum 20, the washing water and the detergent are supplied to the drum 20 through the water supply tube 14 and the detergent supply device 15, and the drum 20 is rotated by the driving motor 18 so that the laundry is washed.

In comparison to the conventional drum washing machine shown in FIG. 1, in which washing water is supplied to the tub 11, in the drum washing machine of the present invention the washing water is supplied directly to the drum 20, thereby reducing consumption of the washing water. The washing water is supplied directly to the drum 20, therefore it is important to prevent the washing water from being discharged to the outside of the drum 20 in the washing mode and to discharge the washing water to the outside of the drum 20 only during the dehydrating mode.

The drum washing machine of the present invention further comprises an opening and closing device 40 (see FIG. 4), which closes the dehydration holes 21 in the washing mode so as to prevent the washing water from being discharged from the drum 20 and opens the dehydration holes 21 in the dehydrating mode so as to discharge the washing water from the drum 20. During the dehydrating mode, the drum 20 is rotated at a high speed and a strong centrifugal force is applied to the drum 20. The opening and closing device 40 opens the dehydration holes 21 using the centrifugal force only when the drum 20 is rotated more than a designated rotational speed.

The opening and closing device 40 comprises opening and closing members 42, and an elastic member to enable the opening and closing members 42 to open or close the dehydration holes according to an intensity of the centrifugal force. That is, the opening and closing members 42 close the dehydration holes 21 by means of the elastic force of the elastic member when the drum 20 is rotated at a low speed, and open the dehydration holes 21 by means of the centrifugal force when the drum 20 is rotated more than a designated speed. The rotational speed of the drum 20 is determined by the weight of the opening and closing members 42 and the intensity of the elastic force of the elastic member.

FIG. 4 illustrates an exploded perspective view of outer and inner surfaces of a drum of the drum washing machine shown in FIG. 2, and FIG. 5 illustrates a cross sectional view taken along the line I-I of FIG. 4.

As shown in FIGS. 4 and 5, the elastic member comprises an elastic band 41, which is wound on an outer cylindrical surface of the drum 20 at a position corresponding to the dehydration holes 21, and applies elastic force towards a center of drum 20. The dehydration holes 21 are aligned in a line along the circumferential surface of the drum 20 in consideration of a shape of the elastic band 41.

The opening and closing members 42 are disposed between the corresponding dehydration holes 21 and the elastic band 41, and close the dehydration holes 21 when a centrifugal force stronger than the elastic force of the elastic band 41 is not applied to the opening and closing members 42, thereby preventing the washing water from being discharged to the outside. Sealing members 43 to prevent the washing water from being leaked through gaps between the opening and closing members 42 and the dehydration holes 21 are respectively interposed between the opening and closing members 42 and the dehydration holes 21.

The opening and closing members 42 comprise spherical shapes having a radius smaller than that of the dehydration holes 21. However, the shape of the opening and closing members 42 is not limited hereto, and may vary. Therefore, when the opening and closing members 42 are mounted on the dehydration holes 21, the opening and closing members 42 are partially inserted into the drum 20 through the dehydration holes 21, thus more firmly closing the dehydration holes 21.

The opening and closing members 42 comprise a sufficient weight so that the centrifugal force stronger than the elastic force of the elastic band 41 is applied to the opening and closing members 42 when the drum 20 is rotated more than a designated speed. However, when the opening and closing members 42 comprise an excessively large weight, the opening and closing members 42 are separated from the dehydration holes 21, or open the dehydration holes 21 even when the drum 20 is rotated at a low speed. Therefore, the weight of the opening and closing members 42 must be appropriately determined in consideration of a rotational speed of the drum 20 and the intensity of the elastic force of the elastic band 41.

As an alternative, the opening and closing members 42 may be separated from the elastic band 41 and located between the dehydration holes 21 and the elastic band 41. However, as shown in this embodiment, the opening and closing members 42 are attached to the elastic band 41 at positions corresponding to the dehydration holes 21. Thereby, it is possible to prevent the opening and closing members 42 from being separated from positions for closing the elastic band 41 corresponding to the dehydration holes 21.

The elastic band 41 is fixed with the drum 20 by connection means, such as screws 50. Therefore, it is possible to prevent the elastic band 41 from being separated from a designated position. When the lifters 30 and the elastic band 41 are fixed with the inner and outer cylindrical surface of the drum 20 by the same connection means, a time taken to assemble the washing machine is shortened, and thus the productivity of the washing machine is improved.

Hereinafter, with reference to FIGS. 3, 6A and 6B, an operation of the above-described opening and closing device 40 will be described in detail.

FIG. 6A illustrates a view of an opening and closing member 42 closing a dehydration hole of the drum washing machine according to an embodiment of the present invention, and FIG. 6B illustrates a view of the opening and closing member 42 opening the dehydration hole of the drum washing machine according to an embodiment of the present invention. Specifically, FIG. 6A illustrates the opening and closing member 42 in a washing mode, and FIG. 6B illustrates the opening and closing member 42 in a dehydrating mode.

As shown in FIG. 6A, in the washing mode of the drum washing machine, the drum 20 is rotated in clockwise and counterclockwise directions at a low speed (for example, approximately 50rpm) so that the laundry in the drum 20 is washed. At this time, a centrifugal force corresponding to a rotational speed of the drum 20 is applied to the opening and closing members 42. Since the intensity of the elastic force of the elastic band 41 surrounding the opening and closing members 42 is stronger than the centrifugal force, the opening and closing members 42 close the dehydration holes 21, thereby preventing the washing water in the drum 20 from being discharged to the outside.

As shown in FIG. 6B, in the dehydrating mode of the drum washing machine, the drum 20 is rotated at a high speed (for example, approximately 600 rpm). At this time, a strong centrifugal force is applied to the opening and closing members 42, and the opening and closing members 42, against the elastic force of the elastic band 41, are separated from the dehydration holes 21 by a designated distance. Then, the washing water in the drum 20 is discharged to the tub 11 through the opened dehydration holes 21, and the washing water in the tub 11 is discharged to the outside through the drainage tube 17 connected to the tub 11. When the rotational speed of the drum 20 is gradually decreased after the dehydrating mode, the opening and closing members 42 are returned to their original positions by the elastic force of the elastic band 41, thereby closing the dehydration holes 21.

As apparent from the above description, the present invention provides a drum washing machine, in which washing water having an amount required by a drum with a volume smaller than that of a tub is supplied to the drum so as to wash laundry in the drum, thereby reducing consumption of the washing water.

Further, the drum washing machine of the present invention comprises an opening and closing device, which maintains the closed states of dehydration holes in a washing mode and opens the dehydration holes only in a dehydrating mode, and supplies the washing water directly to the drum, thereby eliminating problems regarding the leakage or discharge of the washing water.

Although the embodiment of the invention has been shown and described, it would be appreciated by those skilled in the art that changes may be made in this embodiment without departing from the principles and spirit of the invention, the scope of which is defined in the claims and their equivalents. 

1. A drum washing machine comprising a housing and a drum rotatably installed in the housing, wherein a plurality of dehydration holes for discharging washing water is formed through the drum, and the drum washing machine comprising: an opening and closing device to open the dehydration holes by applying a centrifugal force only when the drum is rotated more than a designated speed.
 2. The drum washing machine as set forth in claim 1, wherein the opening and closing device comprises: opening and closing members to open and close the dehydration holes; and an elastic member to enable the opening and closing members to open and close the dehydration holes according to an intensity of the centrifugal force generated due to a rotation of the drum.
 3. The drum washing machine as set forth in claim 1, wherein the dehydration holes are arranged at a front portion of the drum.
 4. The drum washing machine as set forth in claim 2, wherein the elastic member comprises an elastic band wound on an outer cylindrical surface of the drum at a position corresponding to the dehydration holes to apply an elastic force to the drum.
 5. The drum washing machine as set forth in claim 4, wherein the opening and closing members are disposed between the dehydration holes and the elastic band.
 6. The drum washing machine as set forth in claim 5, wherein the opening and closing members comprise spherical shapes, and when the opening and closing members are mounted on the dehydration holes, the opening and closing members are partially inserted into the drum through the dehydration holes so that the washing water in the drum is not discharged to an outside of the drum.
 7. The drum washing machine as set forth in claim 5, wherein the opening and closing members are attached to the elastic band at positions corresponding to the dehydration holes.
 8. The drum washing machine as set forth in claim 4, wherein the dehydration holes are aligned in a line along a circumferential surface of the drum.
 9. The drum washing machine as set forth in claim 4, wherein the elastic band is fixed to the drum by connection means.
 10. The drum washing machine as set forth in claim 9, further comprising lifters fixed with an inside of the drum to lift laundry in the drum to a designated height, wherein the elastic band and the lifters are fixed with the drum by a same connection means.
 11. The drum washing machine as set forth in claim 2, wherein the opening and closing device further comprising sealing members interposed between the dehydration holes and the opening and closing members, to prevent the washing water from being leaked through gaps between the opening and closing members and the dehydration holes.
 12. A drum washing machine having a drum, the drum washing machine comprising: dehydration holes aligned along a surface of the drum to discharge washing water; and an opening and closing device to open the dehydration holes during a dehydration operation when the drum is rotated more than a predetermined speed and to close the dehydration holes during a washing operation.
 13. The drum washing machine of claim 12, further comprising a water supply tube to supply the washing water directly into the drum during the washing operation.
 14. The drum washing machine of claim 13, wherein the opening and closing device comprises: opening and closing members corresponding to the dehydration holes, to open and close the dehydration holes; and an elastic member positioned along an outer surface of the opening and closing members to apply an elastic force to the opening and closing members during the washing operation to close the dehydration holes.
 15. The drum washing machine of claim 14, wherein the opening and closing members close the dehydration holes via the elastic force of the elastic member during the washing operation, and open the dehydration holes via a centrifugal force during the dehydration operation when the drum is rotated more than the predetermined speed.
 16. The drum washing machine of 15, further comprises sealing members respectively interposed between the opening and closing members and the dehydration holes, adjacent to the dehydration holes to prevent the washing water from leaking through gaps between the opening and closing members and the dehydration holes.
 17. The drum washing machine of claim 15, wherein a weight of the opening and closing members is determined relative to a rotational speed and an intensity of the elastic force of the elastic member such that the centrifugal force is stronger than the elastic force during the dehydration operation, to thereby open the dehydration holes during the dehydration operation. 